UFC heavyweight champion Brock Lesnar is critically ill with an undisclosed aliment that could keep him out of the MMA ring for several months, USA TODAY reported on Sunday.

Lesnar was previously diagnosed with infectious mononucleosis (also known as “Mono”) which kept him bedridden for over two weeks. According to the UFC President Dana White, the fighter’s health took a turn for the worse, and a second, undisclosed illness was discovered after he was admitted to hospital.

“It’s bad..It’s real bad. I am worried about it. I can’t really talk about it right now, but [Lesnar] is in rough shape,” White told Yahoo Sports Sunday. White went on to say that at the request of Lesnar, the UFC would not be disclosing the nature of the “serious illness.” “He’s in a hospital up in North Dakota somewhere right now. He went to Canada and some bad stuff happened to him, so we’ve got to figure it out … He doesn’t want to talk about it publicly, but he’s in bad shape. He’s not well and he’s not going to be getting well anytime soon,” White added.

Lesnar has pulled out of his UFC 106 fight and his scheduled fight January 2 against Shane Carwin.

Get well soon, Brock….